Diameter-selective Raman scattering from vibrational modes in carbon nanotubes
Diameter-selective Raman scattering from vibrational modes in carbon nanotubes
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DOI：
10.1126/science.275.5297.187
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发表时间：
1997-01-10
期刊：
影响因子：
56.9
通讯作者：
Dresselhaus, MS
中科院分区：
文献类型：
--
作者：
Rao, AM;Richter, E;Dresselhaus, MS
采用拉曼散射技术研究了在514.5 ~ 1320 nm范围内的激光激发下，以晶体绳状紧密排列的单壁碳纳米管（SWNT）。观察到许多拉曼峰，并与扶手椅对称（n，n）单壁碳纳米管的振动模式。拉曼光谱与基于C-C力常数的晶格动力学计算非常一致，该C-C力常数用于拟合单个石墨烯片的二维实验声子色散。从一个非共振，键极化率模型优化sp（2）碳的计算强度也定性与拉曼数据，虽然共振拉曼散射过程也发生。这种共振是由纳米管中电子的一维量子限制引起的。
Single wall carbon nanotubes (SWNTs) that are found as close-packed arrays in crystalline ropes have been studied by using Raman scattering techniques with laser excitation wavelengths in the range from 514.5 to 1320 nanometers. Numerous Raman peaks were observed and identified with vibrational modes of armchair symmetry (n, n) SWNTs. The Raman spectra are in good agreement with lattice dynamics calculations based on C-C force constants used to fit the two-dimensional, experimental phonon dispersion of a single graphene sheet. Calculated intensities from a nonresonant, bond polarizability model optimized for sp(2) carbon are also in qualitative agreement with the Raman data, although a resonant Raman scattering process is also taking place. This resonance results from the one-dimensional quantum confinement of the electrons in the nanotube.